<img src="/img/tutorial/path-operation-configuration/image01.png">

### Tags with Enums

If you have a big application, you might end up accumulating **several tags**, and you would want to make sure you always use the **same tag** for related *path operations*.

In these cases, it could make sense to store the tags in an `Enum`.

**FastAPI** supports that the same way as with plain strings:

```Python hl_lines="1  8-10  13  18"

```Python hl_lines="10-12"
{!../../docs_src/response_headers/tutorial001.py!}
```

/// note | "Technical Details"

You could also use `from starlette.responses import Response` or `from starlette.responses import JSONResponse`.

@ruy//
EOF

  license_query "attr('licenses', 'notice', deps($BUILD_TARGET))" > $BATS_TEST_TMPDIR/expected_licenses
  license_query "deps($LICENSES_TARGET)" > $BATS_TEST_TMPDIR/actual_licenses

  # Column 1 is left only, Column 2 is right only, Column 3 is shared lines
  # Select lines unique to actual_licenses, i.e. extra licenses.

    /**
     * Return the sAMAccountName of this SID unless it could not
     * be resolved in which case the numeric RID is returned. If this
     * SID is a domain SID, this method will return an empty String.
     * 
     * @return the account name
     */
    String getAccountName ();


    /**
     * Return the domain name of this SID unless it could not be

    /*
     * In principle, a Multimap implementation could add e3 first before failing on the null. But
     * that seems unlikely enough to be worth complicating the test over, especially if there's any
     * chance that a permissive test could mask a bug.
     */
    expectUnchanged();
    // Be extra thorough in case internal state was corrupted by the expected null.

     *
     * T0 at 0 seconds
     * T1 at 1.05 seconds
     * T2 at 2 seconds
     * T3 at 3 seconds
     *
     * Due to the slight delay of T1, T2 would have to sleep till 2.05 seconds, and T3 would also
     * have to sleep till 3.05 seconds.
     */
    return create(permitsPerSecond, SleepingStopwatch.createFromSystemTimer());
  }

  @VisibleForTesting

      "input": null,
      "url": "https://errors.pydantic.dev/2.1/v/missing"
    }
  ]
}
```

As `needy` is a required parameter, you would need to set it in the URL:

```
http://127.0.0.1:8000/items/foo-item?needy=sooooneedy
```

...this would work:

```JSON
{
    "item_id": "foo-item",
    "needy": "sooooneedy"
}
```

And also that you are not sending any data that should have been filtered by a `response_model`.

///

### More info

/// note | "Technical Details"

You could also use `from starlette.responses import Response` or `from starlette.responses import JSONResponse`.

That way, the sub-application will know to use that path prefix for the docs UI.

And the sub-application could also have its own mounted sub-applications and everything would work correctly, because FastAPI handles all these `root_path`s automatically.

```

In this case, `fluffy` is an instance of the class `Cat`.

And to create `fluffy`, you are "calling" `Cat`.

So, a Python class is also a **callable**.

Then, in **FastAPI**, you could use a Python class as a dependency.

What FastAPI actually checks is that it is a "callable" (function, class or anything else) and the parameters defined.